A wide variety of fluid absorbent structures known in the art absorb body fluids such as blood, urine, menses, and the like, and are sanitary and comfortable in use. Disposable products of this type generally comprise a liquid-permeable topsheet, an absorbent core, and a liquid-impermeable backsheet. Various shapes, sizes and thicknesses of such articles have been explored in an attempt to make their use more comfortable and convenient.
Many body fluids have an unpleasant odor, or develop such odors when in contact with air and/or bacteria for prolonged periods. Odor control in sanitary products has been under investigation for many years. Various odor-controlling agents have been disclosed in the literature. For example, U.S. Pat. No. 4,525,410, Hagiwara et al., issued Jun. 25, 1985, discloses zeolite particles (doped with bactericidal cations) held in a fibrous web by incorporating some portion of meltable fibers in the web, and applying heat. These compositions can be used as the outside cover layer in general sanitary goods.
U.S. Pat. No. 2,690,415, F. A. Shuler, issued Sep. 28, 1954, discloses particles of odor-absorbing materials uniformly affixed at the interstices of a permeable web by adhesive to provide an odor absorbent medium; e.g., catamenials. Particulate carbon, silica gel and activated alumina are noted. Shifting/displacement of the particulates is assertedly avoided and the sheet is flexible.
ABSCENTS (odor-control molecular sieve from Union Carbide) for use in diapers and catamenials are specifically noted in Union Carbide brochure (A. J. Gioffre 1988). The brochure indicates that Union Carbide's market research shows potential benefits in such products. U.S. Pat. Nos. 4,795,482 and 4,826,497, relate to ABSCENTS used as an odor-controlling agent, generally, and in sanitary products, in particular.
Activated carbon is a very effective odor absorber, with average internal surface area of about 1000 m.sup.2 /g. However, activated carbon is not readily incorporated into consumer products.
Zeolites have smaller surface area, in the range of about 400-800 m.sup.2 /g. However, zeolites may absorb the moisture in body fluids (i.e., water) over other fluids, which may compromise its effectiveness. Furthermore, activated carbon and zeolites have open structures, and continuously absorb airborne organic vapor, unless hermetically sealed. Therefore, during storage, these odor adsorbents can become saturated and less efficient before the products are used.
Consumers desire not to be exposed to body malodor and to feel "fresh" during the course of the wear of a sanitary napkin. Thus, the present invention provides fragrance bursts of perfume either prior to the placement of the sanitary napkin, use of the sanitary napkin, and/or at its removal from a wearer's undergarments. In addition, a pleasant fragrance may be sustained by the use of microcapsules which diffuse perfume during wear of the sanitary napkin.